Field of the Invention
The present invention relates to a molding compact for forming a transdermal absorption sheet on which a needle-shaped protruding parts are arranged, and a manufacturing method for the transdermal absorption sheet.
Description of the Related Art
Conventionally, most methods for administering a medicine (drug) through a living body surface, that is, a skin or a mucous membrane are mainly methods in which a liquid substance or a powdery substance is attached. However, the attachment region of these substances is limited to the surface of the skin. Therefore, the attached medicine and the like are sometimes removed by sweating or the contact of a foreign substance, and the administration of the proper dose is difficult. Further, when the medicine penetrates deep into the skin, it is difficult to surely control the penetration depth in the method utilizing such a penetration of the medicine by diffusion. Therefore, it is difficult to obtain a sufficient drug effect.
Therefore, there has been performed a method in which a transdermal absorption sheet having needle-shaped protruding parts arranged thereon is used, the needle-shaped protruding parts are inserted into the skin, and thereby the medicine is infused. As a method for forming such a transdermal absorption sheet, a cast molding method using a mold (cast) that includes needle-shaped recessed parts is known. A solution composed of a resin polymer and a drug is poured into the mold that includes the needle-shaped recessed parts. After drying, it is bonded to a fixing substrate, and the separation transfer is performed. It is thereby possible to obtain the transdermal absorption sheet.
The needles, each of which has a base diameter of 50 to 500 μm and a height of 50 to 200 μm, are arranged in an array. For performing the needling into the skin with no pain, it is preferable to use a thin needle that has a high aspect ratio and that has a pointed end as sharp as possible. Further, as this material, a material having biocompatibility and biodegradability is used. Moreover, a drug is previously added to the material, and the transdermal absorption sheet is bonded to the skin. It is thereby possible to release the drug into the skin.
However, in the cast molding method, since the needle-shaped recessed part of the mold has a very minute dimension, a problem occurs that the solution is not easily filled into the needle-shaped recessed part due to the air and surface tension. Hence, Japanese Patent Application Laid-Open No. 2011-78617 (hereinafter, “PTL 1”) describes that a through hole penetrating to the opposite surface of the mold is provided at the bottom of the needle-shaped recessed part of the mold, whereby even when the air stays in the needle-shaped recessed part of the mold, the air easily comes out, so that the needle material can be filled into a recessed part of a stamper.
Further, in Japanese Patent Application Laid-Open No. 2012-200572 (hereinafter, “PTL 2”), the needle material filled into the needle-shaped recessed part of the mold is sucked from a through hole in a back surface of a base-member, at the timing when a step of applying a force such as drying stress and shearing force is performed, whereby the needle material is secured in the needle-shaped recessed part. Therefore, it is described that the separation of the needle material from the needle-shaped recessed part can be prevented against the force such as drying stress and shearing force.